MS, be sure you understand that shot charge is not a substitute for known pressure. You need loads of both light (3/4 to 7/8 oz) shot charge and low pressure (say, sub 7000 psi). Such loads can be purchased from vendors such as RST or made up from handloading data. Low recoil (velocity and shot charge) for you and the wood and low pressure for the metal.

Enjoy.

DDA